Automobile mufflers are likely to suffer development of holes from exposure to corrosive, high temperature environments. It is costly to replace these mufflers, but there has been no ready means of patching the developing holes because of the uniquely aggressive combination of heat and corrosion agents acting on the muffler. Other parts of the engine exhaust system, e.g. headers, and of the engine block may also need a repair which is resistant to chemical attack and high temperature degradation resistant.
In most applications of repair materials the ease and accuracy of applying the repair composition is paramount after performance standards are met. An ideal repair composition will be readily formed in the hole being repaired, and easily convertible there to a permanent fill material. Putty like materials are easily formed to the shape needed, and readily converted to a permanent fill. But conventional putty materials are not chemically resistant nor temperature resistant sufficiently to be used as muffler repair materials.